Making Cartilage from Umbilical Cord Stem Cells Without Growth Factors


Loïc Reppel and his colleagues at CNRS-Université de Lorraine in France have found that mesenchymal stem cells from human umbilical cord can not only be induced to make cartilage, but that these remarkable cells can make cartilage without the use of exogenous growth factors.

Mesenchymal stromal/stem cells from bone marrow (BM-MSC) have, for some time, been the “all stars” for cartilage regeneration. In fact, a very innovative clinic near Denver, CO has pioneered the use of BM-MSCs for patients with cartilage injuries. Chris Centeno, the mover and shaker, of this clinic has carefully documented the restoration of articular cartilage in many patients in peer-reviewed articles.

However, there is another “kid’ on the cartilage-regeneration block; mesenchymal stromal/stem cells from Wharton’s jelly (WJ-MSC). The advantages of these cells are their low immunogenicity and large cartilage-making potential. In this paper, which was published in Stem Cell Research and Therapy, Reppel and others evaluated the ability of WJ-MSCs to make cartilage in three-dimensional culture systems.

Reppell and his coworkers embedded WJ-MSCs isolated from the umbilical cords of new-born babies in alginate/hyaluronic acid hydrogel and grew them for over 28 days. These hydrogels were constructed by the spraying method. The hydrogel solution (for those who are interested, it was 1.5 % (m/v) alginate and hyaluronic acid (ratio 4:1) dissolved in 0.9 % NaCl) was sprayed an airbrush connected to a compressor. The solution was seeded with WJ-MSCs and then sprayed on a sterile glass plate. The hydrogel was made solid (gelation) in a CaCl 2 bath (102 mM for 10 minutes). Then small cylinders were cut (5 mm diameter and 2 mm thickness) with a biopsy punch. Then Reppel and others compared the chondrogenic differentiation of WJ-MSC in these three-dimensional scaffolds, without adding growth factors with BM-MSC.

Illustration of protocol steps used to perform scaffold construct and chondrogenic differentiation. After monolayer expansion, MSC were seeded at 3× 10 6 cells/mL of Alg/HA hydrogel. Hydrogel was sprayed, gelated, and cut into 5 mm diameter cylinders; scale bar = 5 mm. Scaffolds were cultivated in a 48-well plate in differentiation medium for 28 days. Alg/HA alginate/hyaluronic acid, MSC mesenchymal stromal/stem cells, P3 passage 3
Illustration of protocol steps used to perform scaffold construct and chondrogenic differentiation. After monolayer expansion, MSC were seeded at 3× 10 6 cells/mL of Alg/HA hydrogel. Hydrogel was sprayed, gelated, and cut into 5 mm diameter cylinders; scale bar = 5 mm. Scaffolds were cultivated in a 48-well plate in differentiation medium for 28 days. Alg/HA alginate/hyaluronic acid, MSC mesenchymal stromal/stem cells, P3 passage 3

After 3 days in culture, WJ-MSCs seemed nicely adapted to their new three-dimensional culture system without any detectable damage. From day 14 – 28, the proportion of WJ-MSC cells that expressed all kinds of cell surface proteins characteristic of MSCs (i.e., CD73, CD90, CD105, and CD166) decreased significantly. This suggests that these cells were differentiating into some other cell type.

After 28 days in this scaffold culture, both WJ-MSCs and BM-MSCs showed strong upregulation of cartilage-specific genes. However, WJ-MSCs exhibited greater type II collagen synthesis than BM-MSCs, and these differences were evident at the RNA and protein levels. Collagen II is a very important molecule when it comes to cartilage synthesis because chondrogenesis, otherwise known as cartilage production, occurs when MSCs differentiate into cartilage-making cells known as chondroblasts that begins secreting aggrecan and collagen type II that form the extracellular matrix that forms cartilage. Unfortunately, in order to complete the run to mature cartilage formation, the chrondrocytes must enlarge (hypertrophy), and express the transcription factor Runx2 and secrete collagen X. Unfortunately, WJ-MSCs expressed Runx2 and type X collagen at lower levels than BM-MSCs in this culture system.

Matrix synthesis detected after 28 days of chondrogenic induction. Proteoglycans and total collagen were stained by Alcian blue and Sirius red (a), respectively. To explore the synthesis of various collagens in depth, immunofluorescence (b) and immunohistochemistry staining (c) were performed and detected using fluorescence microscopy and light microscopy, respectively; scale bar = 100 μm. BM-MSC bone marrow-derived mesenchymal stromal/stem cells, WJ-MSC Wharton’s jelly-derived mesenchymal stromal/stem cells
Matrix synthesis detected after 28 days of chondrogenic induction. Proteoglycans and total collagen were stained by Alcian blue and Sirius red (a), respectively. To explore the synthesis of various collagens in depth, immunofluorescence (b) and immunohistochemistry staining (c) were performed and detected using fluorescence microscopy and light microscopy, respectively; scale bar = 100 μm. BM-MSC bone marrow-derived mesenchymal stromal/stem cells, WJ-MSC Wharton’s jelly-derived mesenchymal stromal/stem cells

These experiments only examined cells in culture, which is not the same as placing cells in a living animal, but it is a start. Thus, when they are seeded in the hydrogel scaffold, WJ-MSCs and BM-MSCs, after 4 weeks, were able to adapt to their environment and express specific cartilage-related genes and matrix proteins in the absence of growth factors. In order to properly make cartilage in clinical applications, WJ-MSCs must go the full way and express high levels of Runx2 and collagen X. However, these experiments show that WJ-MSCs, which in the past were medical waste, are a potential alternative source of stem cells for cartilage tissue engineering.

Reppel and his colleagues note in their paper that to improve cartilage production from WJ-MSCs, it might be important to mimic the physiological environment in which chondrocytes normally find themselves. For example, they could apply mechanical stress or even a low-oxygen culture system. Additionally, Reppel and others could apply stratified cartilage tissue engineering. Reppel thinks that they could adapt their spraying method to design new stratified engineered tissues by applying progressive cells and spraying hydrogel layers one at a time.

All in all, cartilage repair based with WJ-MSC embedded in Alginate/Hyaluronic Acid hydrogel will hopefully be tested in laboratory animals and then, perhaps, if all goes well, in clinical trials.

Scientists Grow New Diaphragm Tissue In Laboratory Animals


The diaphragm is a parachute-shaped muscle that separates the thoracic cavity from the abdominopelvic cavity and facilitates breathing. Contraction of the diaphragm increases the volume of the lungs, thus dropping the pressure in the lungs below the pressure of the surrounding air and causing air to rush into the lungs (inhalation). Relaxation of the diaphragm decreases the volume of the lungs and increases the pressure in the lungs so that it exceeds the pressure of the air, and air leaves the lungs (exhalation). The diaphragm is also important for swallowing. One in 2,500 babies are born with malformations or perforations in their diaphragms, and this condition is usually fatal.

The usual treatment for this condition involves the construction of an artificial patch that properly covers the lesion, but has no ability to grow with the infant and is not composed of contractile tissue. Therefore, it does not assist in contraction of the diaphragm to assist in breathing.

A new study might change the prospects for these newborn babies. Tissue engineering teams from laboratories in Sweden, Russia and the United States have successfully grown new diaphragm tissue in rats by applying a mixture of stem cells embedded in a 3D scaffold made from donated diaphragm tissue. Transplantation of this stem cell/diaphragm matrix concoction into rats allowed the animals to regrow new diaphragm tissue that possessed the same biological characteristics as diaphragm muscle.
The techniques designed by this study might provide the means for repairing defective diaphragms or even hearts.

Doris Taylor, who serves as the director of regenerative medicine research at the Texas Heart Institute and participated in this revolutionary study, said: “So far, attempts to grow and transplant such new tissues have been conducted in the relatively simple organs of the bladder, windpipe and esophagus. The diaphragm, with its need for constant muscle contraction and relaxation puts complex demands on any 3D scaffold. Until now, no one knew whether it would be possible to engineer.”

Paolo Macchiarini, the director of the Advanced Center for Regenerative Medicine and senior scientist at Karolinska Institutet, who also participated in this study, said: “This bioengineered muscle tissue is a truly exciting step in our journey towards regenerating whole and complex organs. You can see the muscle contracting and doing its job as well as any naturally grown tissue.”

To make their tissue engineered diaphragms, the team used diaphragm tissue that had been taken from donor rats. They stripped these diaphragms of all their cells, but maintained all the connective tissue. This removed anything in these diaphragms that might cause the immune systems of recipient animals to reject the implanted tissue, while at the same time keeping all the things that give the diaphragm its shape and form. In the laboratory, the decellularized diaphragms had lost all their elasticity. However, once these diaphragm matrices were seeded with bone marrow-derived stem cells and transplanted into recipient laboratory animals, the diaphragm scaffolds began to function as well as normal, undamaged diaphragms.

If this new technique can be successfully adapted to human patients, it could replace the damaged diaphragm tissue of the patient with tissue that would constantly contract and grow with the child. Additionally, the diaphragm could be repaired by utilizing a child’s own stem cells. As a bonus, this technique might also provide a new way to

Next, the team must test this technique on larger animals before it can be tested in a human clinical trial.

The study was published in the journal Biomaterials.

Porous Hydrogels Boost Stem Cell-Based Bone Production


Regenerative medicine relies upon the ability to isolate, manipulate, and exploit stem cells from our own bodies or from the bodies of stem cell donors. A present obstacle to present therapeutic strategies is the poor survival of implanted stem cells. There are also worries of about properly directing the differentiation of transplanted stem cells. After all, if implanted stem cells do not differentiate into the terminal cell types you want to be replaced, the use of such cells seems pointless.

To address this problem, David Mooney from the Wyss Institute and his colleagues have designed a three-dimensional system that might keep transplanted stem cells alive and happy, ready to heal.

Mooney’s group has adopted a strategy based on the concept of stem cell “niches.”. In our bodies, stem cells have particular places where they live. These stem cell-specific microenvironments provide unique support systems for stem cells and typically include extracellular matrix molecules to which stem cells attach.

Mooney and others have identified chemical and physical cues that act in concert to promote stem cell growth and survival. The chemical cues found in stem cell niches are relatively well-known but the physical and mechanical properties are less well understood at the present time.

Stem cells in places like bone, cartilage, or muscle, when cultured in the laboratory, display particular mechanical sensitivities and they must rest on a substrate with a defined elasticity and stiffness in order to proliferate and mature. As you might guess, reproducing the right physical properties in the laboratory is no mean feat. However, several laboratories have used hydrogels to generate the right combination of chemical and physical properties.

Mooney and his colleagues have made two hydrogels with very different properties. A stable, “bulk” gel is filled with small bubbles of a pore-making molecule called a “porogen,” which degrades quickly and leaves porous cavities in its wake. When the bulk hydrogel is combined with extracellular matrix molecules from stem cell niches and filled with tissue-specific stem cells, and the porogen, Mooney and his team can make an artificial bone-forming stem cell niche. The porous cavities in the hydrogel, in combination with the chemical signals, drive the stem cells to grow, and divide while expanding into the open spaces in the gel. Then the cell move from the hydrogel to form mineralized bone.

In small animal experiments, Mooney and his colleagues showed that a porous hydrogel with the correct chemical and elastic properties provides better bone regeneration than transplanting stem cells alone. The maturing stem cells deployed by the hydrogel also induce neighboring stem cell populations to contribute to the bone repair, which further amplifies their regenerative effects.

This study provides the first demonstration that adjusting the physical properties of a biomaterial can not only help deliver stem cells but also tune the behavior of those cells in a living organism. Even though Mooney has primarily focused on bone formation, he and his group believe that the hydrogel concept can be broadly applied to other regenerative process as well.

This work was published in Nature Materials 2015; DOI: 10.1038/nmat4407.

Biomaterial Sponge-Like Impant Traps Spreading Cancer Cells


Prof Lonnie Shea, from the Department of Biomedical Engineering at the University of Michigan and his team have designed a small sponge-like implant that has the ability to mop up cancer cells as they move through the body. This device has been tested in mice, but there is hope that the device could act as an early warning system in patients, alerting doctors to cancer spread. The sponge-like implant also seemed to stop rogue cancer cells from reaching other areas where they could establish the growth of new tumors. Shea and others published their findings in the journal Nature Communications.

According to Cancer Research UK, nine in 10 cancer deaths are caused by the disease-spreading to other areas of the body. Stopping the spread of cancer cells, or metastasis, is one of the ways to prevent cancers from becoming worse. Complicating this venture is the fact that cancer cells that circulate in the bloodstream are rare and difficult to detect.

Shea’s device is about 5mm or 0.2 inches in diameter and made of a “biomaterial” already approved for use in medical devices. So far, this implant has so far been tested in mice with breast cancer. Implantation experiments showed that it can be placed either in the abdominal fat or under the skin and that it tended to suck up cancer cells that had started to circulate in the body.

Cancer Cell Trapping Implants

The implant mimicked a process known as chemoattraction in which cells that have broken free from a tumor are attracted to other areas in the body by immune cells. Shea and others found that these immune cells are drawn to the implant where they “set up shop.” This is actually a natural reaction to any foreign body, and the presence of the immune cells also attracts the cancer cells to the implant.

Initially, Shea and others labeled cancer cells with fluorescent proteins that caused them to glow under certain lights, which allowed them to be easily spotted. However, they eventually went on to use a special imaging technique that can distinguish between cancerous and normal cells. They discovered that they could definitively detect cancer cells that had been caught within the implant.

Unexpectedly, when they measured cancer cells that had spread in mice with and without the implant, they showed that the implant not only captured circulating cancer cells, but it also reduced the numbers of cancer cells present at other sites in the body.

Shea, said that he and his team were planning the first clinical trials in humans fairly soon: “We need to see if metastatic cells will show up in the implant in humans like they did in the mice, and if it’s a safe procedure and that we can use the same imaging to detect cancer cells.”

Shea and his coworkers are continuing their work in animals to determine what the outcomes if the spread of the cancer spread was detected at a very early stage, which is something that is presently not yet fully understood.

Lucy Holmes, Cancer Research UK’s science information manager, said: “We urgently need new ways to stop cancer in its tracks. So far this implant approach has only been tested in mice, but it’s encouraging to see these results, which could one day play a role in stopping cancer spread in patients.”

Using Silk to Grow Salivary Glands in the Laboratory


Colloquially, we use the word “spit” to describe saliva, which is secreted by our salivary glands. Saliva is a complex combination of water, salts, proteins, small molecules, and other components that lubricate our throats and mouths to facilitate swallowing, coat our gums and teeth to maintain good gum health and keep tooth decay at bay, and keep our breath fresh. Insufficient salivation production increases tooth decay rates, causes chronic halitosis (bad breath), and can swallowing difficult. Additionally, there are no treatments for poorly-functioning salivary glands, and these glands have poor regenerative capabilities.

Patients who suffer from head/neck cancers and have been treated with radiation suffer from “xerostoma” or dry mouth. Certain medications can also cause dry mouth as can old age. 50% of older Americans suffer from xerostoma.

If that isn’t bad enough, salivary glands are notoriously hard to grow in the laboratory.  So they slow down when we grow old, do not regenerate and grow poorly, in at all, in the laboratory.  Is there any good news about salivary glands?

Make that a yes!  A research team from the University of Texas Health Science Center, led by Chih-Ko Yeh has discovered a process that may lead to the growth of salivary glands in cell culture.  Yeh and his team used purified silk fibers that had many of their contaminants removed to grow salivary stem cells from rat salivary glands.  These cells grew in the laboratory and after several weeks in culture, generated a three-dimensional matrix that covered the silk scaffolds and shared many characteristics with the salivary glands that grow in the mouth.

Yeh underscored the importance of this discovery: “Salivary gland stem cells are some of the most difficult cells to grow in culture and retain their function.”  This work in Yeh’s laboratory have is the first time that salivary gland stem cells have been grown in cell culture while retaining their salivary gland properties.

Yeh continued, “The unique culture system has great potential for future salivary gland research and for the development of new cell-based therapeutics.”

Silk, contrary to what you might think, is an excellent choice for stem cell scaffolding because it is natural, biodegradable, flexible, porous material that provides cells easy access to oxygen and nutrition.  Silk also does not cause inflammation, which is a problem with other types of stem cell scaffolds.

Since there are so few salivary gland stem cells in the human mouth, Yeh and his group plan to continue using the rat model to refine their techniques.  Eventually, Yeh and others would like to use stem cells derived from bone marrow or umbilical cord blood to regenerate salivary glands in human patients.

In fact, Yeh and his coworkers have pioneered protocols for harvesting large numbers of bone marrow stem cells from bone marrow and human umbilical cord blood and growing them in culture.  These stem cells are abundant and can be differentiated into different cell types by means of tissue engineering technologies.

Yeh hopes that by the next decade, human salivary stem cells or tissue engineered artificial salivary gland will be used to initiate salivary gland regeneration in human patients.

This research was published in Tissue Engineering part A 2015; 21(9-10).

3-D Printing to Make Replacement Body Parts


Advances in three-dimensional (3D) printing have produced a swell of interest in artificial organs that are designed to replace, or even enhance, human tissues.

3-D printed organs

At the Inside 3D Printing conference in New York on April 15–17, 2015, researchers from academia and industry are gathering to discuss the growing interest in using three-dimensional (3D) printing to make replacement body parts. Although surgeons are already using 3D-printed metal and plastic implants to replace bones, researchers are looking ahead to printing organs using cells as “ink.”  All the structures shown here were all 3D printed at Wake Forest Baptist Medical Center in Winston-Salem, North Carolina, and include a rudimentary proto-kidney (top left), complete with living cells.

Printed organs, such as a prototype outer ear that was developed by researchers at Princeton University in New Jersey and Johns Hopkins University in Baltimore, Maryland, will be featured at the conference.  This ear is printed from a range of materials: a hydrogel to form an ear-shaped scaffold, cells that will grow to form cartilage, and silver nanoparticles to form an antenna (see M.S. Mannoor et al. Nano Lett. 13, 2634−2639; 2013. This is just one example of the increasing versatility of 3D printing.

This New York meeting, which is being advertised as the largest event in the industry, will provide exposure for a whole world of devices and novelties. But it will also feature serious discussions on the emerging market for printed body parts.

The dream of bioprinting is to print organs that can be used for transplant. For example, at the Wake Forest Baptist Medical Center in Winston-Salem, North Carolina, researchers are developing a 3D-printed kidney. The project is in its early stages and the kidney is far from functional and some doubt that researchers will ever be able to print such a complex organ. Perhaps a more achievable near-term goal might be to print sheets of kidney tissue that could be grafted onto existing kidneys.

Printed replacement for skull

Printed structures made of hard metal or polymers are already on the market for people in need of an artificial hip, finger bone or facial reconstruction. This skull implant (grey) was made by Oxford Performance Materials of South Windsor, Connecticut, and was approved by US regulators in 2013. It is made of a polymer meant to encourage bone growth, to aid integration of the implant into the surrounding skeleton. The company also sells implants for facial reconstruction and for replacing small bones in the feet and hands.

3-D printed lung tree

One of the key advantages of using 3D printing for surgical implants is the opportunity to model the implant to fit the patient. This airway splint (shown on the right branch of the model trachea) was designed by researchers at the University of Michigan in Ann Arbor to fit an infant with a damaged airway. The splint was made out of a material that is gradually absorbed by the body as the airway heals. The research team benefited from the concentration of 3D-printing expertise that has built up in Michigan because of the US automobile industry, which uses the technology for printing prototypes and design samples.

The business of 3-D printing also includes titanium replacement hip joints, which can be tailored to fit individual people, and made-to-order polymer bones to reconstruct damaged skulls and fingers. Printed body parts brought in US $537 million last year, up about 30% on the previous year, says Terry Wohlers, president of Wohlers Associates, a business consultancy firm in Fort Collins, Colorado, that specializes in 3D printing.

3-D printed prosthetics

3D printing can also be used to generate cheap — and creative — prostheses.  A prosthetic hand can cost thousands of dollars, which is a burdensome expense when fitting it to a growing child.  Jon Schull founded a company called e-NABLE that provides free printed prosthetics to those in need, harnessing the efforts of hundreds of volunteers who own consumer-grade 3D printers. “When people get tired of printing Star Wars figurines, they give us a call,” he says.  The cost of materials for a printed prosthesis is about US $35.

3-D animal prosthesis

Also, 3-D printed prostheses are not just for humans.  For example, a duck named Buttercup was born with its left foot turned backwards.  The Feathered Angels Waterfowl Sanctuary in Arlington, Tennessee, arranged for the fowl to receive a new foot, complete with a bendable ankle.  Also in the an eagle, a box turtle and a handful of dogs also have been fitted with 3-D printed prostheses.

Scientists are looking ahead to radical emerging technologies that use live cells as ‘ink’, assembling them layer-by-layer into rudimentary tissues, says Jennifer Lewis, a bioengineer at Harvard University in Cambridge, Massachusetts. Bioprinting firm Organovo of San Diego, California, already sells such tissues to researchers aiming to test experimental drugs for toxicity to liver cells. The company’s next step will be to provide printed tissue patches to repair damaged livers in humans, says Organovo’s chief executive, Keith Murphy.

Lewis hesitates to say that 3D printing will ever yield whole organs to relieve the shortage of kidneys and livers available for transplant. “I would love for that to be true,” she says. “But these are highly complicated architectures.”

Bone Marrow Stem Cells and Tissue Engineering Give a Woman a New Smile


Massive injuries to the face can cause bone loss and “tooth avulsion.” Medically speaking, avulsion simply refers to the detachment of a body structure from its normal location by means of surgery or trauma. Dental implants and help with lost teeth, but if the facial bone has suffered so much loss that you cannot place implants in them, then you are out of luck. Dental prostheses can help, but these do not always fit very well.

Darnell Kaigler and his group at the University of Michigan Center for Oral Health wanted to help a 45-year-old woman who had lost seven teeth and a good portion of her upper jaw bone (maxilla) as a result of massive trauma to the face. This poor lady had some dentures that did not fit well and a mouth that did not work well.

Bone can be grown from stem cells, but getting those stem cells to survive and do what you want them to do is the challenge of regenerative medicine. Therefore, Dr. Kraigler and his group used a new technique to help this young lady, and their results are reported in the December 2014 issue of the journal Stem Cells Translational Medicine.

First, Kraigler and his co-workers extracted bone marrow stem cells from a bone marrow aspiration that was taken from the upper part of the hip bone (the posterior crest of the ilium for those who are interested).  They used a product called ixmyelocel-T from Aastrom Biosciences in Ann Arbor , MI. This product is a patient-specific, expanded multicellular therapy, cell-processing system that selectively expands mesenchymal cells, monocytes and alternatively activated macrophages, up to several hundred times more than the number found in the patient’s bone marrow, while retaining many of the hematopoietic cells collected from only a small sample (50ml) of the patient’s bone marrow. Thus, the healing cells from the bone marrow are grown and made healthy, after which the cells were bagged and frozen for later use.

ixmyelocel-T

Then the patient was readied for the procedure by having the gum tissue cut and lifted as a flap of tissue (under anesthesia, or course). Then four holes were drilled into the bone and setting screws were inserted. This is an important procedure, because implanted stem cells will not survive unless they have blood vessels that can bring them oxygen and nutrients. By drilling these holes, the tissue responds by making new blood vessels. To this exposed surface, the bone marrow-derived stem cells were applied with a tricalcium phosphate (TCP). TCP is a salt that will induce mesenchymal stem cells to form bone. Once the TCP + stem cell mixture was applied to the gum, a collagen membrane was placed over it, and the gum was then sewn shut with sutures.

Cell transplantation procedure. Front view (A) and top view (B) of the initial clinical presentation showing severe hard and soft tissue alveolar ridge defects of the upper jaw. Following elevation of a full-thickness gingival flap, the images show front view (C) and top view (D) of the severely deficient alveolar ridge, clinically measuring a width of only 2–4 mm. Front view (E) and top view (F) of the placement of “tenting” screws in preparation of the bony site to receive the graft. Placement of the β-tricalcium phosphate (seeded with the cells 30 minutes prior to placement at room temperature) into the defect (G), with additional application of the cell suspension following placement of the graft in the recipient site (H). Placement of a resorbable barrier membrane (I) to stabilize and contain the graft within the recipient site, and top view (J) of primary closure of the flap.
Cell transplantation procedure. Front view (A) and top view (B) of the initial clinical presentation showing severe hard and soft tissue alveolar ridge defects of the upper jaw. Following elevation of a full-thickness gingival flap, the images show front view (C) and top view (D) of the severely deficient alveolar ridge, clinically measuring a width of only 2–4 mm. Front view (E) and top view (F) of the placement of “tenting” screws in preparation of the bony site to receive the graft. Placement of the β-tricalcium phosphate (seeded with the cells 30 minutes prior to placement at room temperature) into the defect (G), with additional application of the cell suspension following placement of the graft in the recipient site (H). Placement of a resorbable barrier membrane (I) to stabilize and contain the graft within the recipient site, and top view (J) of primary closure of the flap.

Four months later, the patient underwent a cone-beam computed tomography (CBCT) scan. The bone regrowth can be seen in the figure below.

Cone-beam computed tomography (CBCT) scans. CBCT scans were used to render three-dimensional reconstructions of the anterior segment of the upper jaw and cross-sectional (top view) radiographic images to show volumetric changes of the upper jaw at three time points. (A, B): The initial clinical presentation shows 75% jawbone width deficiency. (C, D): Immediately following cell therapy grafting, there is full restoration of jawbone width. (E, F): Images show 25% resorption of graft at 4 months and overall net 80% regeneration of the original ridge-width deficiency.
Cone-beam computed tomography (CBCT) scans. CBCT scans were used to render three-dimensional reconstructions of the anterior segment of the upper jaw and cross-sectional (top view) radiographic images to show volumetric changes of the upper jaw at three time points. (A, B): The initial clinical presentation shows 75% jawbone width deficiency. (C, D): Immediately following cell therapy grafting, there is full restoration of jawbone width. (E, F): Images show 25% resorption of graft at 4 months and overall net 80% regeneration of the original ridge-width deficiency.

According to the paper, there was an “80% regeneration of the original jawbone.”

Into this newly regenerated bone, permanent dental implants were placed. The results are shown below.

Complete oral rehabilitation. Clinical presentation of the patient prior to initiation of treatment (A) and following completed oral reconstruction (B). (C): Periapical radiographs of oral implants showing osseointegration of implants and stable bone levels at the time of placement, 6 months following placement, and 6 months following functional restoration and biomechanical loading of implants with a dental prosthesis.
Complete oral rehabilitation. Clinical presentation of the patient prior to initiation of treatment (A) and following completed oral reconstruction (B). (C): Periapical radiographs of oral implants showing osseointegration of implants and stable bone levels at the time of placement, 6 months following placement, and 6 months following functional restoration and biomechanical loading of implants with a dental prosthesis.

Pardon me, but permit me an unprofessional moment when I say that this is really cool.  Of course, this patient will need to be observed over the next several years to determine the longevity of her bone regeneration, but the initial result is certainly something to be excited about.

Tricalcium phosphate or TCP has been used to induce the bone-making activities of mesenchymal stem cells.  It has also been used in several animal studies as a delivery vehicle for mesenchymal stem cells (for example, see Rai B, et al., Biomaterials 2010, 31:79607970; Krebsbach PH, et al., Transplantation 1997, 63:10591069; Zhou J, et al., Biomaterials 2010, 31:11711179).  TCP also seems to support stem cell proliferation, survival, and differentiation into bone.  Kresbach and others showed that TCP most consistently yielded bone formation when used as a delivery vehicle for mesenchymal stem cells compared to other biomaterials commonly used, such as gelatin sponges and demineralized bone matrix.  However, there are no studies that have ascertained how well stem cells attach to TCP, and this attachment is an important factor in determining how many stem cells reach the site of injury.  This study by Kaigler and his group (A. Rajan and others) showed that a 30-minute incubation of the cells with TCP gave sufficient attachment of the cells to the TCP for clinical use.  The efficiency of this incubation period was also not affected by the temperature.  

The other exciting features of this paper, is that most of the materials used in this study were commercially available.  The bone marrow stem cell isolation technique was pioneered by Dennis JE, and others in their 2007 article in the journal Stem Cells (25:25752582).  Effective commercialization of this technique has shown the efficacy of this procedure for clinical use.  This paper also shows the clinical feasibility of using TCP as a delivery vehicle for mesenchymal stem cell-based bone treatments.

In conclusion, I will quote the authors: “Cell survival and seeding efficiency in the context of tissue engineering and cell-therapy strategies are critical parameters for success that have not been rigorously examined in a clinical context. This study defined optimized conditions for these parameters using an autologous stem cell therapy to successfully treat a patient who had a debilitating craniofacial traumatic deficiency. To our knowledge, there have been no other clinical reports of cell therapy for the treatment of craniofacial trauma defects. This clinical report serves as solid foundation on which to develop more expanded studies using this approach for the treatment of larger numbers of patients with other debilitating conditions (e.g., congenital disorders) to further evaluate efficacy and feasibility.”